The present invention relates to a device for sealing surfaces between a motor shaft and a motor end cover of a pressure medium-driven rotary vane-type motor.
A pressure chamber sealing arrangement for a hydraulically operated vane-type or impeller motor has been disclosed in DE-AS No. 130 3585. In this conventional arrangement, the pressure chambers are sealed by triangular pressure rings which are pre-stressed in the direction of the sealing surfaces. The sealing principle has been based on a partial lifting of the sealing ring from the sealing surfaces.
The disadvantage of this known sealing arrangement resides in that, due to the stream of the pressure medium flowing into the sealing gap an erosion occurs, and also the sealing gap becomes contaminated by particles contained in the pressure medium whereby increased wear of the sealing surfaces takes place and the gap is enlarged. Leakage is also increased while a friction force is enhanced and efficiency is reduced.
A further disadvantage of the known sealing device resides in shorter lengths of the guiding faces of the sealing ring, which can cause clamping and twisting of the pressure ring.
Furthermore, the motor has a great number of the sealing surfaces and thus is expensive to manufacture.